A geometric figure or object that lacks symmetry or cannot be divided into equal parts.
From Greek 'a-' (not) plus 'symmetron' (that which is symmetrical), from 'sym-' (together) plus 'metron' (measure), with the Greek noun suffix '-on'.
This is such a rare technical term that it barely appears in any dictionaries—mathematicians mostly just say 'asymmetric figure' instead of trying to use this mouthful.
Complete word intelligence in one call. Free tier — 50 lookups/day.